Hi,
Does anyone have Meraki documentation related to BGP best-path selection algorithm?
From my testing environment I've noticed that a MX in one-armed concentrator mode (the only mode that supports eBGP) always prefers the eBGP route over iBGP route (it doesn't care of AS-PATH length)
Ex:
R1(AS 100)----eBGP----HUB1-----iBGP(AS 65100)-----HUB2----R2 (AS 200)
R1 advertises subnet 10.10.10.10/32 with AS path 100 100 100
R2 advertises subnet 10.10.10.10/32 with AS path 200
--> Hub1 prefers the external route from R1 (would expect to prefer the route from Hub2)
--> Hub2 prefers the external route from R2 (expected behavior)
--> If R1 stops advertising 10.10.10.10/32, then Hub1 will receive the route from Hub2 via iBGP with AS PATH 65100 200
--> If Spoke 1 has in the hub list HUB1(primary) HUB2(secondary), it will prefer the route from HUB2 with AS PATH 65100 200
thanks